1. Field of the Invention
This invention relates to the field of unloading devices for removing catalyst from within the tubes of a reactor.
In unloading flowable granular or particle catalyst from the tubes of a multi-tube reactor, difficulties have been encountered in removing catalyst that has become lodged within the tubes during reactor operation. In some previous instances, the particle catalyst completely blocked or bridged some or all of the tubes of the reactor due to heat, composition changes and the like, and retarded or blocked movement or flow of the catalyst from the tubes of the reactor.
2. Description of the Prior Art
U.S. Pat. No. 3,916,960 discloses an apparatus for unloading catalyst which includes a head positionable adjacent open ends of a plurality of reactor tubes for creating a pressure differential in the reactor tubes for flowing the catalyst from the reactor tubes into a chamber formed by the head. The head mounts a manifold system having a plurality of lances of appropriate preselected length and diameter discharging a controlled stream of fluid into the tubes for dislodging bridging catalyst in the reactor tubes and circulating the catalyst from the tubes.
In U.S. Pat. No. 4,820,496, several tubes can be unloaded by gravity, and the stuck or bridge-over catalyst can be dislodged by reciprocation or by air jets with essentially complete containment of dust and with complete recovery of catalyst. Additionally, Applicant acknowledges prior use of a hand-cranked air lance reel by BASF, Inc. a Louisiana corporation. This unit was similar to a garden hose reel. No literature is available.